The present invention relates, in general, to a clutch release bearing for use in a clutch operator, and more particular to a sealing arrangement for use in a clutch release bearing.
Various approaches are known to seal a clutch release bearing in order to prevent ingress of dirt and moisture into the rolling-contact bearing and escape of lubricant out of the clutch release bearing. German Pat. Publication DE 195 03 217 A1 describes a clutch release bearing for release of a separating clutch, including a torsionally rigid outer bearing ring, which is secured to a housing or axially shiftable guide sleeve of the clutch release bearing, a revolving inner bearing ring, which is connected via a spring element to the separating clutch, and rolling elements, which are received in a cage and guided between the bearing rings. Two seals are provided in sliding contact with the revolving bearing ring. A first seal is mounted to the rigidly fixed outer bearing ring and includes two spread-apart sealing lips which are supported by a cylindrical portion of the revolving inner bearing ring. A second seal is secured to the housing or guide sleeve and has a sealing lip resting against the revolving inner bearing ring. The sealing lips of the seals, which are all in sliding contact with the inner bearing ring, increase friction and thus expose the clutch release bearing to more heat. As a result, lubricant is subject to greater stress and there is a risk of premature failure of the clutch release bearing so that the service life is shortened. Seals for a clutch release bearing of this type are therefore unsuitable for many applications. In particular, there is a danger that the engagement disk of the separating clutch causes swirling rubbed-off parts in the clutch housing, which accommodates the clutch release bearing, to migrate via the sealing lip into the clutch release bearing.
It would therefore be desirable and advantageous to provide an improved clutch release bearing which obviates prior art shortcomings and which realizes an enhanced sealing action, while still being simple in construction.